Blackberry Jam Canning Recipe and Jam Tips

So back in April, we were lucky enough to pick over 3 gallons of blackberries down in Plaquemines Parish, AKA zone 9b where it never gets below 40 (rarely).  Technically they are dewberries, but they might as well be blackberries, just really huge ones.  Anyways seeing that we had a ton of them, I made a bunch of jams (24+ half pints?), pie filling, “chocolate blackberry sauce”, and froze a bunch.  The jams turned out really good, which surprised me in some ways considering I never made jam before (only marmalade previously).

Homemade jams

Homemade jams

So onto some recipes.  I used the “Ball Blue Book of Canning” recipe for the Blackberry Chocolate Sauce (well they call it Chocolate Raspberry Sundae Topper) which you can find their recipe here or here if you don’t have that book.  I ended up doubling the amount of cocoa powder and I still don’t think it is chocolatey enough, but it does taste really good so its not all bad.  One side note is that I hated the fact that I had to use commercial pectin 🙁 but I figured it was worth it for chocolate haha.

Ok so onto the recipe that I made the bulk of the jams with which came out of “The Blue Chair Jam Cookbook” by Rachel Saunders.  This book is just amazing and just because I am sorta sharing the recipe with you, I still think you should get the book.  Well only if of course if you are planning on making any jams, jellies, marmalades, etc.  She doesn’t use any commercial pectins, Woooo!!!  Which besides the fact that I don’t want to eat them, she teaches you how to make jam the traditional way to create the jell instead of just adding powdered pectin.  I am all for trying the traditional way to make foods since those ways were a tradition for a reason meaning they are tried and true.  Also a very big thank you to my sister Susie, she gave me this book and the Flavor Bible book that I mention later.

Anyways here is the recipe: Wild Blackberry Jam (makes 5 half pints)


1 lb+ 6 oz. blackberries

2 lb+ 2 oz. blackberries

1 3/4 lb white cane sugar

2 1/2 to 3 oz. fresh lemon juice

Optional ingredients:

~1 to 3 tsp cinnamon

~Swapping the white sugar with brown sugar

~Lemon zest

How to:

Combine the 1 lb+ 6 oz. of blackberries with the sugar and lemon juice in a wide pot (11 to 12 quart is what she suggests, more on that later).  Heat on medium-low stirring very frequently until the juice begins to run from the berries.  Then turn the heat up to high, continuing to stir, until it boils (basically don’t worry about mashing up the berries here, you really just don’t want it to burn).  Keep it boiling for 3 to 4 minutes (STIR!).

Add the rest of the blackberries (the 2 lb, etc), and bring it back up to a boil making sure to keep stirring often.  Once boiling again, cook the jam for 10 to 15 more minutes with frequent stirring.  Start testing for doneness after 10 minutes with the frozen plate method or however you like.  I found that I went for 15 minutes at least (or 20?), maybe this was because I was using big dewberries and not regular wild blackberries.

Processing the jars:

Leave a 1/4 inch headspace and water bath process the jars for 10 minutes for half pint jars.  For 12 oz jelly jars, I processed for 15 minutes for safety though I am not sure it needs the extra 5 minutes or not (see canning tips).


  • Add flavor add ins (spices or liquor/wine).  I really liked adding the cinnamon to the jam, I thought it gave the jam another depth of flavor which turned out lovely when used for yogurt+jam.  Also the lemon zest is a nice touch as well.  I got these ideas from The Flavor Bible book that I always double check when I am cooking.  Which as a side note, is damn useful for making up dishes on the fly about what goes well together.  For example: sweet potatoes roasted with onions, rosemary, and bacon (its a great combo).  Other options for flavoring for blackberries include: nutmeg, ginger, cardamon, clove, lime zest, and even sage (though I don’t have the balls to try sage yet, would be a sad panda if a whole batch of jam turned out crappy).
  • Watch jam like a hawk when you are cooking it.  When I was making the marmalades last December, I lost a batch because I stupidly let it burn on the bottom.  Don’t let that happen to you!  It sucked so don’t get distracted.
  • Use a wide pot with pretty tall sides.  I tried making some jam in my dutch oven and that was a mistake.  It was wide enough so evaporation wasn’t going to be an issue (which is why you want a wide pot by the way, that isn’t just because) but it was too short when it came to the rolling boil stage.  It was down right dangerous/messy so I ended up using my stock pot which is overkill but it works.  I wish I had one of the copper jam kettles that Rachel mentions in the book, they sound awesome.
  • Be hesitant in buying the 12 oz jam jars.  I bought them when I didn’t really have any idea about canning since the canning section at Walmart was ransacked when I went there (its the cheapest for jars in the area…).  They work fine, you can certainly make fine jam and can in them; however, no recipes are going to tell you how long to process them for since nobody seems to use them.  Now I just added 5 minutes to the usual half pint processing time, but I honestly don’t know if that was necessary or enough.  Obviously nobody has gotten botulism or reported anything to me (thanks family for being guinea pigs :D) so I am going to just say it worked fine.  But if you are a n00b like me, just don’t buy them and then you won’t have to speculate whether it worked out ok.

Some final thoughts

I really enjoyed making the jams and it turned out to be a great way to put up a bunch of blackberries that we didn’t have freezer space for.  Now we have jam that can be used to make desserts, make flavored yogurt, on toast of course, for on top of ice cream, to be eaten plain… etc etc.  It may seem like a pain, but I really suggest you try it out.


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